The currently accepted procedure for left atrial access involves routing a needle called a Brockenbrough needle into the right atrium with the Brockenbrough needle pre-placed within a guiding catheter. The guiding catheter specifically preferred for use with a Brockenbrough needle is called a Mullins catheter or transseptal introducer. The Brockenbrough needle is a long, small diameter punch, generally formed from a stainless steel wire stylet that is surrounded by a stainless steel tube.